Deraeocoris gorczycai Kim, Taszakowski & Jung, 2023

Kim, Junggon, Taszakowski, Artur & Jung, Sunghoon, 2023, A new genus and two new species of fossil deraeocorine plant bugs (Hemiptera: Heteroptera: Miridae) from Eocene Baltic amber, Zootaxa 5382 (1), pp. 170-178 : 174-176

Deraeocoris gorczycai Kim, Taszakowski & Jung , sp. nov.

( Fig. 2 )

Type material: [ CNU] Holotype: Male specimen in a 37×12× 8 mm elongate cabochon shaped light brown piece of amber. Dorsal surface rounded. Lateral and ventral surfaces flat. Amber internally with a large bubble on left side of specimen. No syninclusions. Collection code CNUHHMF007.

Diagnosis: Differs from the extinct fossil species Deraeocoris balticus by the following characters: body shorter than 5 mm, partly pale brown (vs body larger than 5 mm, mostly dark brown) ( Fig. 2A ); third antennomere shorter than fourth antennomere (vs third one longer than fourth one) ( Figs. 2B, C, E ); pronotal collar entirely pale brown (vs pronotal collar dark); calli clearly separated (vs calli fused in anterior side) ( Figs. 2A, C, D ); and hind tarsus longer than 1/3 hind tibia (vs hind tarsus shorter than 1/3 hind tibia) ( Fig. 2G ).

Differs from the extant congeners of Deraeocoris s. lat. by the following combination of characters: body partly pale and dark brown; head mostly dark brown, vertex pale brown; neck entirely dark brown; first antennomere entirely dark brown, second antennomere pale on basal 2/3 and dark on apical 1/3; third antennomere shorter than fourth antennomere; pronotal collar entirely pale brown; pronotum mostly dark brown, posterior margin paler; scutellum mostly pale brown with dark two spots; hemelytra partly pale and dark, clavus mostly dark brown; legs mostly dark brown; tarsus longer than 1/3 tibia; first tarsomere shortest, third tarsomere longest, subequal to combined length of first and second tarsomeres.

Description: Male: Body elongate oval, length 4.58 mm. Coloration. Partly pale and dark brown. Head: partly brown and dark brown, with remarkable dark structures; carina dark brown; neck entirely dark brown; first antennomere entirely dark brown, second antennomere mostly brown with darker apical part; third antennomere mostly dark brown with paler basal part; fourth antennomere mostly dark brown; labium mostly dark brown, apex of each labial segment pale brown. Thorax: pronotum mostly dark brown, posterior margin pale brown; pronotal collar entirely pale brown; scutellum pale brown with dark spots, mesoscutum brown, unicolorous to dark spots on scutellum; hemelytron mostly pale brown, inner margins of clavus and corium dark brown; embolial margin pale brown; membrane subhyaline, veins dark brown; legs partly brown and dark browns; femur mostly dark brown, apical part of each femora paler; tibia brown with dark annulations; tarsus mostly brown, with dark apex of third tarsal segment. Abdomen: mostly dark brown in ventral view. Surface and vestiture. Body glossy, partly punctate, densely covered with short setae; head impunctate, covered with short setae; thorax mostly glossy, partly punctate, covered with dense setae; pronotum totally polished, punctate, densely covered with setae; scutellum glossy, impunctate, covered with dense setae; hemelytra glossy, slightly punctate, covered with dense setae; embolium area impunctate; leg with spines; abdomen covered with long setae. Structure. Head: prognathous, length shorter than width, shorter than pronotal midline; vertex narrow, narrower than compound eye width; compound eye large, ventral margin proximate to ventral suture of maxillary plate; antennae generally linear, shorter than body length; second antennomere clearly thicker than third, fourth antennomere; third antennomere shorter than fourth antennomere; labium reaching hind coxae. Thorax: pronotum trapezoidal, anterior width shorter than head width, posterior margin strongly rounded; pronotal midline length as long as 1/2 of basal width, longer than scutellum midline; pronotal collar subequal to first antennomere diameter; scutellum somewhat small, slightly swollen ( Fig. 2F ); commissure length longer than scutellum midline length; lateral margin of hemelytra slightly rounded; cuneus elongate, inner margin sinuate; legs slender; combined length of hind femur and hind tibia shorter than body length; hind tarsus longer than 1/3 hind tibia; first tarsomere shortest, third tarsomere longest, subequal to combined length of first and second tarsomeres. Abdomen: elongate, reaching apex of cuneus.

Measurements (in mm): body length: 4.58; head length 0.47; head width including compound eyes: 0.76; vertex width: 0.19; first antennomere length: 0.37; second antennomere length: 1.48; third antennomere length: 0.54; fourth antennomere length: 0.70; first labial segment: 0.45; second labial segment: 0.43; third labial segment: 0.55; fourth labial segment: 0.59; pronotal midline length: 0.83; basal pronotal maximal width (straight): 1.27; anterior scutellar width: 0.55; scutellar midline length: 0.61; commissure length: 0.75; outer embolial margin length (straight): 2.01; hindleg (femur: tibia: tarsus): 1.59: 2.02: 0.59.

Type locality and stratum: Unknown locality on the Baltic Sea Coast, Poland or Russia, mid-Eocene (ca. 44.1±1.1 Ma) ( Wappler, 2005) .

Etymology: Named after well-known mirid taxonomist Jacek Gorczyca, one of the authors of the deraeocorine fossil Deraeocoris balticus ; noun in genitive case.

Remarks: We tentatively placed this fossil into the genus Deraeocoris , as the proportions of the antennomeres and the tarsomeres differ from those of most Deraeocoris species. In particular, the tarsomere proportion is important as a character at the generic level ( Kim et al. 2023; e.g., Alloeotomus Fieber, 1858 with the longest first tarsomere). Nonetheless, except for these two structures, it is true that the other structures of this fossil species are morphologically most similar to those of Deraeocoris s. lat. for the moment, even though the Deraeocoris s. lat. was not recovered as monophyletic, and the apomorphy on the tarsal structure was not found ( Kim et al. 2023). In addition, several Deraeocoris species have a similar proportion of the tarsomeres (e.g., Deraeocoris ainoicus Kerzhner, 1979 ). Therefore, further study of the Deraeocorini is needed for the generic placement of Deraeocoris gorczycai sp. nov.

Figures

FIGURE 2. Deraeocoris gorczycai sp. nov., holotype (CNUHHMF007). A, dorsal habitus. B, lateral habitus. C, dorso-lateral habitus. D, head, pronotum and scutellum. E, antennae. F, head and pronotum in lateral view. G, hind tarsus. Scale bars: 1 mm.